Thank for all the replies.
What I decided on is to get a regular 1.8m (7 foot) desk, and some quick-setup shelves behind the desk, for the full length of it. Then I'll install a DIY rollup cover at the top of the shelving, to cover just the shelving, and install some permanent sides on the shelving. All the expensive gear will go on the shelving at the rear, and if any expensive gear needs to be in closer proximity to me, I can move it temporarily onto my desk and then put it back onto the shelf when finished, and pull down the cover to hid the gear.
As mentioned, trying to cover the entire desk might mean the sheet/cover would easily snag on equipment and tear the cover and/or knock over items while the cover is being removed. So the vertical rollup cover just in front of the shelves should solve that problem, I think. If I need the cover to extend down to the floor, there will need to be a bit of a gap between the desk and shelving, but I don't think that'll make much of a problem.
One further reason for me keeping the gear covered and out of sight is my desire to not show it to friends who might want to borrow it. At the previous company I worked for, they had a very liberal policy of sharing equipment. Each year tens of thousands of dollars of equipment I needed to do my job was damaged due to coworkers borrowing it and damaging it, due to carelessness, inexperience, etc. My boss was the worst offender, so I couldn't easily complain to him about the stupidity of the policy of allowing anyone to borrow any other person's equipment. Well, I know most all my friends / acquaintances would be conscientious about using someone's personal stuff, but still if it's not your own, or you don't know how to use it well, it's only a matter of time before it gets abused / damaged. It's far easier to just keep the equipment hidden, so nobody knows it's there, so nobody will want to borrow it.
As for questionable people entering my home, I really don't have control over who a delivery person, inspector, installer is, who might need to enter my home as part of their job.